2023 GMC SIERRA stop start

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 237
With the vehicle moving less than
5 km/h (3 mph) and the transmission in
N (Neutral), attempt the shift again.
Shifting Out of 4
n
1. The vehicle must be stopped or movingless than 5 km/h (3 mph) with the
transmission in N (Neutral) and the
ignition on. It is best for the vehicle to
be moving 1.6 to 3.2 km/h (1 to 2 mph).
2. Press 4
m, AUTO, or 2m. The actual 4x4
shift request is only made after the
button is released. The 4x4 graphic will
remain flashing until the shift request
has completed. A DIC message displays
to indicate the state of the request.
Once the 4x4 shift has completed, the
DIC message disappears, the 4x4 graphic
stops flashing, and the current setting is
indicated.
If vehicle speed is higher when shift
request occurs, a DIC message displays.
Reduce vehicle speed.
If the transmission is not in N (Neutral)
when shift request occurs, DIC messages will
display. The vehicle will allow 20 seconds for
this shift to occur. After this time, a graphic
in the instrument cluster will indicate that
the transfer case is in 4
n.
Caution
Shifting the transmission into gear before
the requested mode indicator light has
stopped flashing could damage the
transfer case.
If the transmission is not shifted into
N (Neutral) or the vehicle has not slowed to
5 km/h (3 mph) within 20 seconds, the
transfer case will remain in its original state.
This will be indicated in the instrument
cluster.
With the vehicle moving less than 5 km/h
(3 mph), and the transmission in N (Neutral),
attempt the shift again.
Shifting Into N (Neutral)
To shift into N (Neutral): 1. Start the vehicle.
2. Shift the transmission to N (Neutral).
3. Shift the transfer case to 2
m.
4. Apply the parking brake and/or brake pedal.
5. Press 2
mfive times in 10 seconds until
the N (Neutral) graphic starts flashing in
the instrument cluster. When the shift is
complete, the graphic stops flashing. If the parking brake and/or brake pedal
is not applied within 20 seconds, the
transfer case will remain in the original
state.
6. If the transmission is not shifted into N (Neutral) or the vehicle has not slowed
to 5 km/h (3 mph) within 20 seconds,
the transfer case will remain in its
original state. This will be indicated in
the instrument cluster.
Shifting Out of N (Neutral)
To shift out of N (Neutral): 1. Turn the ignition on with the engine off. See Ignition Positions (Key Access) 0221
or
Ignition Positions (Keyless Access) 0223.
2. Set the parking brake. See Electric
Parking Brake 0239.
3. Shift the transmission to N (Neutral).
4. Shift the transfer case to 2
m. Transfer
case shifts out of N (Neutral) can only be
made into 2
m. When the shift to 2mis
complete, the graphic in the instrument
cluster will stop flashing. If the transfer
case cannot complete a shift, the graphic
will return to the previously selected
setting.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
240 Driving and Operating
If the EPB is applied while the vehicle is
moving, the vehicle will decelerate as long
as the switch is pressed. If the switch is
pressed until the vehicle comes to a stop,
the EPB will remain applied.
The vehicle may automatically apply the EPB
in some situations when the vehicle is not
moving. This is normal, and is done to
periodically check the correct operation of
the EPB system, or at the request of other
safety functions that utilize the EPB.
If the EPB fails to apply, block the rear
wheels to prevent vehicle movement.
EPB Release
To release the EPB:1. Turn the ignition on or to ACC/ACCESSORY.
2. Apply and hold the brake pedal.
3. Press the EPB switch momentarily.
The EPB is released when the red parking
brake status light is off.
If the amber service parking brake warning
light is on, release the EPB by pressing and
holding the EPB switch. Continue to hold the
switch until the red parking brake status
light is off. If either light stays on after
release is attempted, see your dealer.
Caution
Driving with the parking brake on can
overheat the brake system and cause
premature wear or damage to brake
system parts. Make sure that the parking
brake is fully released and the brake
warning light is off before driving.
If you are towing a trailer and parking on a
hill, see Driving Characteristics and Towing
Tips 0268.
Automatic EPB Release
The EPB will automatically release if the
vehicle is running, placed into gear, and an
attempt is made to drive away. Avoid rapid
acceleration when the EPB is applied, to
preserve parking brake lining life.
Brake Assist
Brake Assist detects rapid brake pedal
applications due to emergency braking
situations and provides additional braking to
activate the Antilock Brake System (ABS) if
the brake pedal is not pushed hard enough
to activate ABS normally. Minor noise, brake
pedal pulsation, and/or pedal movement
during this time may occur. Continue to apply the brake pedal as the driving
situation dictates. Brake Assist disengages
when the brake pedal is released.
Hill Start Assist (HSA)
{Warning
Do not rely on the HSA feature. HSA does
not replace the need to pay attention
and drive safely. You may not hear or
feel alerts or warnings provided by this
system. Failure to use proper care when
driving may result in injury, death,
or vehicle damage. See
Defensive Driving
0 205.
When the vehicle is stopped on a grade, Hill
Start Assist (HSA) prevents the vehicle from
rolling in an unintended direction during the
transition from brake pedal release to
accelerator pedal apply. The brakes release
when the accelerator pedal is applied. If the
accelerator pedal is not applied within a few
minutes, the Electric Parking Brake will
apply. The brakes may also release under
other conditions. Do not rely on HSA to hold
the vehicle.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 241
HSA is available when the vehicle is facing
uphill in a forward gear, or when facing
downhill in R (Reverse). The vehicle must
come to a complete stop on a grade for HSA
to activate.
Ride Control Systems
Traction Control/Electronic
Stability Control
System Operation
The vehicle has a Traction Control System
(TCS) and StabiliTrak/Electronic Stability
Control (ESC) system. These systems help
limit wheel spin and assist the driver in
maintaining control, especially on slippery
road conditions.
TCS activates if it senses any of the drive
wheels are spinning or beginning to lose
traction. When this happens, TCS applies the
brakes to the spinning wheels and reduces
engine power to limit wheel spin.
StabiliTrak/ESC activates when the vehicle
senses a difference between the intended
path and the direction the vehicle is actually
traveling. StabiliTrak/ESC selectively applies
braking pressure to any one of the vehicle
wheel brakes to assist the driver in keepingthe vehicle on the intended path. Trailer
Sway Control (TSC) is also on automatically
when the vehicle is started. See
Trailer Sway
Control (TSC) 0285.
If cruise control is being used and traction
control or StabiliTrak/ESC begins to limit
wheel spin, cruise control will disengage.
Cruise control may be turned back on when
road conditions allow.
Both systems come on automatically when
the vehicle is started and begins to move.
The systems may be heard or felt while
they are operating or while performing
diagnostic checks. This is normal and does
not mean there is a problem with the
vehicle.
It is recommended to leave both systems on
for normal driving conditions, but it may be
necessary to turn TCS off if the vehicle gets
stuck in sand, mud, ice, or snow. See If the
Vehicle Is Stuck 0214 and “Turning the
Systems Off and On” later in this section.
When the transfer case (if equipped) is in
Four-Wheel Drive Low, the stability system
is automatically disabled,
gcomes on, and
the appropriate message will appear on the Driver Information Center (DIC). Both
traction control and StabiliTrak/ESC are
automatically disabled in this condition.
The indicator light for both systems is in the
instrument cluster. This light will:
.Flash when TCS is limiting wheel spin.
.Flash when StabiliTrak/ESC is activated.
.Turn on and stay on when either system
is not working.
If either system fails to turn on or to
activate, a message displays in the Driver
Information Center (DIC), and
dcomes on
and stays on to indicate that the system is
inactive and is not assisting the driver in
maintaining control. The vehicle is safe to
drive, but driving should be adjusted
accordingly.
If
dcomes on and stays on:
1. Stop the vehicle.
2. Turn the engine off and wait 15 seconds.
3. Start the engine.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
242 Driving and Operating
Drive the vehicle. Ifdcomes on and stays
on, the vehicle may need more time to
diagnose the problem. If the condition
persists, see your dealer.
Turning the Systems Off and On
The button for TCS and StabiliTrak/ESC is on
the center stack.
Caution
Do not repeatedly brake or accelerate
heavily when TCS is off. The vehicle
driveline could be damaged.
To turn off only TCS, press and release
g.
The traction off light
idisplays in the
instrument cluster. The appropriate message
will display in the DIC. To turn TCS on again,
press and release
g. The traction off light
idisplayed in the instrument cluster will
turn off. If TCS is limiting wheel spin when
gis
pressed, the system will not turn off until
the wheels stop spinning.
To turn off both TCS and StabiliTrak/ESC,
press and hold
guntil the traction off light
iand the StabiliTrak/ESC OFF lightgcome on and stay on in the instrument
cluster, then release. The appropriate
message will display in the DIC.
To turn TCS and StabiliTrak/ESC on again,
press and release
g. The traction off light
iand the StabiliTrak/ESC OFF lightgin
the instrument cluster turn off.
StabiliTrak/ESC will automatically turn on if
the vehicle exceeds 56 km/h (35 mph).
Traction control will remain off.
The vehicle has a Trailer Sway Control (TSC)
feature and a Hill Start Assist (HSA) feature.
See Trailer Sway Control (TSC) 0285 or
Hill Start Assist (HSA) 0240.
Adding accessories can affect the vehicle
performance. See Accessories and
Modifications 0302.
Hill Descent Control (HDC)
If equipped, Hill Descent Control (HDC) sets
and maintains vehicle speed while driving
down steep grades in a forward or reverse
gear. The HDC switch is on the center stack.
Press
5to enable or disable HDC. Vehicle
speed must be below 50 km/h (31 mph).
When enabled, the HDC light displays on
the instrument cluster.
A blinking HDC light indicates the system is
actively applying the brakes to maintain
vehicle speed. HDC can maintain vehicle
speeds between 1 and 22 km/h (1 and
14 mph) on grades greater than or equal
to 10%.
If HDC is to be used for more than
three minutes or on grades steeper than
25%, the transfer case should be put into
Four-Wheel Drive Low (4
n) to reduce the
possibility of brake overheating.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 265
The starting characteristics of E85 or FlexFuel
make it unsuitable for use when
temperatures fall below−18 °C (0 °F). Use
gasoline or add gasoline to the E85 or
FlexFuel.
Because E85 or FlexFuel has less energy per
liter (gallon) than gasoline, the vehicle will
need to be refilled more often. See Filling
the Tank (Chassis Cab and Box Delete
Models) 0266 or
Filling the Tank (Pickup Models) 0265.
The only GM approved aftermarket additive
is ACDelco Fuel System Treatment
Plus-FlexFuel. Follow the instructions on the
bottle for proper use. This product is
available at your GM dealer.
Caution
Some additives are not compatible with
E85 or FlexFuel and can harm the
vehicle's fuel system. Use only additives
approved by GM for E85 or FlexFuel
vehicles. Damage caused by unapproved
additives would not be covered by the
vehicle warranty.
Caution
Do not use fuel containing methanol.
It can corrode metal parts in the fuel
system and also damage plastic and
rubber parts. That damage would not be
covered under the vehicle warranty.
To help keep the engine running efficiently,
fill the tank with gasoline, up to E15, after
filling the tank with E85 one or two times.
Filling the Tank (Pickup Models)
If the vehicle has a diesel engine, see the
Duramax diesel supplement.
An arrow on the fuel gauge indicates which
side of the vehicle the fuel door is on. See
Fuel Gauge 0115.
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
(Continued)
Warning (Continued)
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.
.Fuel can spray out if the fill nozzle is
inserted too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Insert the
fill nozzle slowly and wait for any hiss
noise to stop before beginning to
flow fuel.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 267
{Warning
Fuel vapors and fuel fires burn violently
and can cause injury or death.
Follow these guidelines to help avoid
injuries to you and others:
.Read and follow all the instructions on
the fuel pump island.
.Turn off the engine when refueling.
.Keep sparks, flames, and smoking
materials away from fuel.
.Do not leave the fuel pump
unattended.
.Avoid using electronic devices while
refueling.
.Do not re-enter the vehicle while
pumping fuel.
.Keep children away from the fuel
pump and never let children
pump fuel.
.Before touching the fill nozzle, touch a
metallic object to discharge static
electricity from your body.(Continued)
Warning (Continued)
.Fuel can spray out if the fuel cap is
opened too quickly. This spray can
happen if the tank is nearly full, and is
more likely in hot weather. Open the
fuel cap slowly and wait for any hiss
noise to stop, then unscrew the cap all
the way.
Turn the fuel cap counterclockwise to
remove. Fully insert and latch the fill nozzle,
begin fueling. For models with dual fuel
tanks, the fuel gauge shows an average of
both tanks. When refueling, refuel the
primary front tank first, then add fuel to the
auxiliary rear tank.
{Warning
Overfilling the fuel tank by more than
three clicks of a standard fill nozzle may
cause:
.Vehicle performance issues, including
engine stalling and damage to the fuel
system.
.Fuel spills.
.Under certain conditions, fuel fires. Be careful not to spill fuel. Wait five seconds
after you have finished pumping before
removing the fill nozzle. Clean fuel from
painted surfaces as soon as possible. See
Exterior Care
0374. Reinstall the cap by
turning it clockwise until it clicks.
{Warning
If a fire starts while you are refueling, do
not remove the fill nozzle. Shut off the
flow of fuel by shutting off the pump or
by notifying the station attendant. Leave
the area immediately.
Caution
If a new fuel cap is needed, get the right
type of cap from your dealer. The wrong
type of fuel cap may not fit properly,
may turn on the malfunction indicator
lamp, and could damage the fuel system
and emissions system. See Malfunction
Indicator Lamp (Check Engine Light)
0 120.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
Driving and Operating 271
When parking your vehicle and your trailer
on a hill:1. Press and hold the brake pedal, but do not shift into P (Park). Turn the wheels
toward the curb if facing downhill or
into traffic if facing uphill.
2. Have someone place chocks under the trailer wheels.
3. Gradually release the brake pedal to allow the chocks to absorb the load of
the trailer.
4. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
5. Release the brake pedal.
Leaving After Parking on a Hill
1. Apply and hold the brake pedal.
.Start the engine.
.Shift into a gear.
.Release the parking brake.
2. Let up on the brake pedal.
3. Drive slowly until the trailer is clear of the chocks.
4. Stop and have someone pick up and store the chocks.
Launching and Retrieving a Boat
Backing the Trailer into the Water
{Warning
.Have all passengers get out of the
vehicle before backing onto the sloped
part of the ramp. Lower the driver and
passenger side windows before
backing onto the ramp. This will
provide a means of escape in the
unlikely event the vehicle slides into
the water.
.If the boat launch surface is slippery,
have the driver remain in the vehicle
with the brake pedal applied while the
boat is being launched. The boat
launch can be especially slippery at
low tide when part of the ramp was
previously submerged at high tide. Do
not back onto the ramp to launch the
boat if you are not sure the vehicle
can maintain traction.
.Do not move the vehicle if someone is
in the path of the trailer. Some parts
of the trailer might be underwater and
not visible to people who are assisting
in launching the boat. Disconnect the trailer wiring before backing
the trailer into the water to prevent damage
to the electrical circuits. Reconnect the
wiring to the trailer after removing the
trailer from the water. If the trailer has
electric brakes that can function when the
trailer is submerged, it might help to leave
the electrical trailer connector attached to
maintain trailer brake functionality while on
the boat ramp.
To back the trailer into the water:
1. If equipped, place the vehicle in Four-Wheel Drive High or Automatic
Four-Wheel Drive.
2. Slowly back down the boat ramp until the boat is floating, but no further than
necessary.
3. Press and hold the brake pedal, but do not shift into P (Park) yet.
4. Have someone place chocks under the front wheels of the vehicle.
5. Gradually release the brake pedal to allow the chocks to absorb the load of
the trailer.
6. Reapply the brake pedal. Then apply the parking brake and shift into P (Park).
7. Release the brake pedal.

GMC Sierra/Sierra Denali 2500 HD/3500 HD Owner Manual (GMNA-
Localizing-U.S./Canada-16504257) - 2023 - CRC - 5/9/22
272 Driving and Operating
Pulling the Trailer from the Water
To pull the trailer out of the water:1. Press and hold the brake pedal.
2. Start the engine and shift into gear.
3. Release the parking brake.
4. Let up on the brake pedal.
5. Drive slowly until the tires are clear of the chocks.
6. Stop and have someone pick up and store the chocks.
7. Slowly pull the trailer from the water.
8. Once the vehicle and trailer have been driven from the sloped part of the boat
ramp, the vehicle can be shifted from
four-wheel-drive high. Shift into the drive
mode that is appropriate for the road
conditions.
Caution
If the vehicle tires begin to spin and the
vehicle begins to slide toward the water,
remove your foot from the accelerator
pedal and apply the brake pedal. Seek
help to have the vehicle towed up
the ramp.
Maintenance when Trailer Towing
The vehicle needs service more often when
used to tow trailers. See Maintenance
Schedule 0385. It is especially important to
check the engine oil, axle lubricant, belts,
cooling system, and brake system before
and during each trip.
Check periodically to see that all nuts and
bolts on the trailer hitch are tight.
Engine Cooling When Trailer Towing
The cooling system may temporarily
overheat during severe operating conditions.
See Engine Overheating 0313.
Trailer Towing
If equipped with a diesel engine, see the
Duramax diesel supplement.
Caution
Towing a trailer improperly can damage
the vehicle and result in costly repairs
not covered by the vehicle warranty. To
tow a trailer correctly, follow the
directions in this section and see your
dealer for important information about
towing a trailer with the vehicle.
Trailering is different than just driving the
vehicle by itself. Trailering means changes in
handling, acceleration, braking, and
durability. Successful, safe trailering takes
correct equipment, and it has to be used
properly.
The following information has many
time-tested, important trailering tips and
safety rules. Many of these are important
for your safety and that of your passengers.
Read this section carefully before pulling a
trailer.